The Morphological properties of SnCl2·2H2O-modified PC/PMMA blends

Abstract

SnCl2·2H2O-modified PC/PMMA (80/20 w/w) blends were prepared by melt blending using a torque rheometer. The effect of SnCl2·2H2O content and blending conditions on the structures, phase morphologies and thermal properties of the blends were investigated by FTIR, SEM, TGA and DSC. The FTIR spectra of the 0.015 % (wt) SnCl2·2H2O-modified PC/PMMA blends showed the characteristic peaks of both PC and PMMA due to the formation of PC-g-PMMA copolymers. From the SEM images, it was demonstrated that the domain size of the dispersed PMMA phase decreased clearly with the increases in SnCl2·2H2O content and the mixing time, but it increased with the incremental increases in the rotor rate before reaching 80 rpm. In addition, a similar co-continuous structure was observed in the two blend systems. The first blend was prepared at a temperature of 270 °C and a rotor rate of 40 rpm for 10 min, and the other blend was prepared at a temperature of 230 °C and a rotor rate of 70 rpm for 10 min. The TGA results showed that there was only one single-step thermal degradation in PC/PMMA blends which contained 0.100 % (wt) SnCl2·2H2O, suggesting the formation of a homogeneous blend of the two phases. The DSC curves demonstrated that the 0.015 % (wt) SnCl2·2H2O modified the PC/PMMA blend systems which were prepared at 230, 240 or 250 °C and displayed only one single glass transition temperature (T g). But, it showed two distinct T gs when the mixing temperature was set at 260 and 270 °C.